[postgis-users] Newbie help

[Nahum Castro]

--- Andy Dale <andy.dale at gmail.com> escribió:

> I have just started using PostGis 1.2.0 on
> Postgresql 8.1.4.  Most of the
> data I wish to store in is Long/Lat type coords in
> the format ((N|S|E|W)
> degrees, minutes, seconds, tenths of seconds,
> hundredths of seconds), with
> the degrees for latitude being 2 digits and degrees
> for longitude being
> 3 digits.  The characters
> N,S,E,W are there just to specify if the relevant
> coord is north/south
> of the equator, or east/west of the zero meridian. 
> Is it possible to
> just store the data in the (D)DD:MM:
> SS.TenthsHundredths format (usually WSG84
> datum) and use them for calculations, or must i
> first convert them to
> the decimal equivalent
> before saving them ?? And if i have to convert can
> postgis perform the
> transformation/calculation for me.
> 
> 
> Cheers,
> 
> Andy
> > _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
>
http://postgis.refractions.net/mailman/listinfo/postgis-users
> 
I use this stored procedure to do that.
----------------------------------------
CREATE or replace FUNCTION convertir_latlon( value
INTEGER ) RETURNS float AS $$
   DECLARE
     arg INTEGER;
     grados float;
     minutos float;
     segundos float;
     dd       float;
     
   BEGIN

     arg := value;
     IF length(arg) = 7 THEN
       BEGIN
         segundos := substr(arg,6,2);
         minutos := substr(arg,4,2);
         grados :=  substr(arg,1,3);
         dd := grados + (minutos/60) +
(segundos/3600); 
         RETURN dd;
       END;
     ELSE
       BEGIN
         segundos := substr(arg,5,2);
         minutos := substr(arg,3,2);
         grados :=  substr(arg,1,2);
         dd := grados + (minutos/60) +
(segundos/3600);
         RETURN dd;
       END;  
     END IF;
   END;
 $$ LANGUAGE 'plpgsql';
-----------------------------------------------------------
modify to suit your needs.

Saludos desde México


--
Nahum Castro
Leon, Guanajuato, Mexico
http://www.leon-linux.com
e-mail: pedro1_72 [en] yahoo [punto] com


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